Methods for the purification of deoxycholic acid
Synthetic methods for preparing deoxycholic acid and intermediates thereof, high purity synthetic deoxycholic acid, compositions and methods of use are provided. Also, provided are processes for the synthesis of 12-keto or 12-α-hydroxysteroids from Δ-9,11-ene, 11-keto or 11-hydroxy-β-steroids. This invention is also directed to novel compounds prepared during the synthesis. This invention is also directed to the synthesis of deoxycholic acid starting from hydrocortisone.
1. A process for preparing a 12-keto compound 3:
the process comprising:
contacting Δ-9,11-ene compound 4:
with an alkylhydroperoxide of the formula (R 3 )(R 4 )(R 5 )C—O—OH in the presence of a co-oxidant to prepare a compound of formula 1:
wherein:
Pg is a hydroxyl protecting group;
R is hydrogen, hydroxyl, or —OPg;
R 1 is the 17-side chain of a bile acid selected from the group consisting of cholic acid, deoxycholic acid, taurocholic acid, and glycocholic acid, wherein the carboxyl functionality of said side chain is optionally esterified with a C 1 -C 6 alkyl group, and R 2 is hydrogen, or R 1 and R 2 together with the carbon atom attached thereto form a keto or a keto protecting group; and
each of R 3 , R 4 , and R 5 is independently C 1 -C 3 alkyl;
converting the compound of formula 1 to compound 2:
under reducing conditions; and
contacting compound 2 with an oxidizing agent to prepare the 12-keto compound 3.
2. The process of claim 1 , wherein compound 4 is contacted with more than one equivalent of tert-butyl hydroperoxide and in the presence of CuI.
3. The process of claim 1 , wherein the co-oxidant is selected from the group consisting of aqueous sodium hypochlorite, palladium on carbon, Pd(OCOCF 3 ) 2 , Pd(OAc) 2 and CuI.
4. The process of claim 1 , wherein the compound of formula 1 is selected from the group consisting of compounds 42, 43, 44, 45 and 46:
5. The process of claim 1 , wherein R 1 is selected from the group consisting of
wherein R 6 is lower alkyl and represents the point of connection to the 17-position of steroidal scaffold.
6. The process of claim 1 , wherein R 1 and R 2 together with the carbon atom attached thereto form a keto group.
7. The process of claim 1 , wherein R 1 and R 2 together with the carbon atom attached thereto form:
wherein n is 1, 2, or 3 and the wavy line represents the point of connection to the rest of the molecule.
8. The process of claim 1 , wherein R is hydrogen.
9. The process of claim 1 , wherein the reducing conditions comprise contact with aqueous sodium sulfite.
10. The process of claim 1 , wherein the oxidizing agent is pyridinium chlorochromate.